LeetCode

A collection of LeetCode questions to ace the coding interview! - Created using LeetHub v2

LeetCode Topics

Divide and Conquer

0004-median-of-two-sorted-arrays
0105-construct-binary-tree-from-preorder-and-inorder-traversal
0106-construct-binary-tree-from-inorder-and-postorder-traversal
0108-convert-sorted-array-to-binary-search-tree
0148-sort-list
0169-majority-element
0190-reverse-bits
0191-number-of-1-bits
0772-construct-quad-tree
0954-maximum-sum-circular-subarray

Bit Manipulation

0190-reverse-bits
0191-number-of-1-bits
0201-bitwise-and-of-numbers-range
0222-count-complete-tree-nodes
0476-number-complement
1054-complement-of-base-10-integer
1435-xor-queries-of-a-subarray
1473-find-the-longest-substring-containing-vowels-in-even-counts
1786-count-the-number-of-consistent-strings
2323-minimum-bit-flips-to-convert-number
2503-longest-subarray-with-maximum-bitwise-and

Array

0004-median-of-two-sorted-arrays
0011-container-with-most-water
0033-search-in-rotated-sorted-array
0034-find-first-and-last-position-of-element-in-sorted-array
0035-search-insert-position
0036-valid-sudoku
0040-combination-sum-ii
0045-jump-game-ii
0046-permutations
0048-rotate-image
0054-spiral-matrix
0055-jump-game
0056-merge-intervals
0057-insert-interval
0068-text-justification
0073-set-matrix-zeroes
0074-search-a-2d-matrix
0079-word-search
0080-remove-duplicates-from-sorted-array-ii
0084-largest-rectangle-in-histogram
0088-merge-sorted-array
0105-construct-binary-tree-from-preorder-and-inorder-traversal
0106-construct-binary-tree-from-inorder-and-postorder-traversal
0108-convert-sorted-array-to-binary-search-tree
0118-pascals-triangle
0122-best-time-to-buy-and-sell-stock-ii
0130-surrounded-regions
0134-gas-station
0139-word-break
0149-max-points-on-a-line
0150-evaluate-reverse-polish-notation
0152-maximum-product-subarray
0153-find-minimum-in-rotated-sorted-array
0162-find-peak-element
0169-majority-element
0179-largest-number
0189-rotate-array
0198-house-robber
0200-number-of-islands
0209-minimum-size-subarray-sum
0212-word-search-ii
0221-maximal-square
0238-product-of-array-except-self
0283-move-zeroes
0289-game-of-life
0373-find-k-pairs-with-smallest-sums
0380-insert-delete-getrandom-o1
0399-evaluate-division
0452-minimum-number-of-arrows-to-burst-balloons
0502-ipo
0539-minimum-time-difference
0624-maximum-distance-in-arrays
0719-find-k-th-smallest-pair-distance
0729-my-calendar-i
0731-my-calendar-ii
0735-asteroid-collision
0772-construct-quad-tree
0859-design-circular-deque
0870-magic-squares-in-grid
0890-lemonade-change
0906-walking-robot-simulation
0921-spiral-matrix-iii
0945-snakes-and-ladders
0954-maximum-sum-circular-subarray
0999-regions-cut-by-slashes
1196-filling-bookcase-shelves
1240-stone-game-ii
1256-rank-transform-of-an-array
1325-path-with-maximum-probability
1435-xor-queries-of-a-subarray
1497-design-a-stack-with-increment-operation
1511-count-number-of-teams
1556-make-two-arrays-equal-by-reversing-subarrays
1615-range-sum-of-sorted-subarray-sums
1620-check-if-array-pairs-are-divisible-by-k
1691-minimum-number-of-days-to-disconnect-island
1694-make-sum-divisible-by-p
1786-count-the-number-of-consistent-strings
1798-max-number-of-k-sum-pairs
1833-find-the-highest-altitude
1923-sentence-similarity-iii
2006-find-the-student-that-will-replace-the-chalk
2035-count-sub-islands
2067-maximum-number-of-points-with-cost
2132-convert-1d-array-into-2d-array
2155-find-missing-observations
2163-kth-distinct-string-in-an-array
2255-minimum-swaps-to-group-all-1s-together-ii
2411-spiral-matrix-iv
2494-sum-of-prefix-scores-of-strings
2503-longest-subarray-with-maximum-bitwise-and
2581-divide-players-into-teams-of-equal-skill
2727-number-of-senior-citizens
2755-extra-characters-in-a-string
3235-minimum-cost-to-convert-string-i
3329-find-the-length-of-the-longest-common-prefix
3501-delete-nodes-from-linked-list-present-in-array

String

0003-longest-substring-without-repeating-characters
0005-longest-palindromic-substring
0006-zigzag-conversion
0012-integer-to-roman
0020-valid-parentheses
0022-generate-parentheses
0030-substring-with-concatenation-of-all-words
0068-text-justification
0071-simplify-path
0072-edit-distance
0076-minimum-window-substring
0079-word-search
0097-interleaving-string
0127-word-ladder
0139-word-break
0151-reverse-words-in-a-string
0179-largest-number
0212-word-search-ii
0214-shortest-palindrome
0224-basic-calculator
0241-different-ways-to-add-parentheses
0273-integer-to-english-words
0394-decode-string
0399-evaluate-division
0433-minimum-genetic-mutation
0539-minimum-time-difference
0564-find-the-closest-palindrome
0567-permutation-in-string
0592-fraction-addition-and-subtraction
0664-strange-printer
0920-uncommon-words-from-two-sentences
1473-find-the-longest-substring-containing-vowels-in-even-counts
1756-minimum-deletions-to-make-string-balanced
1786-count-the-number-of-consistent-strings
1923-sentence-similarity-iii
2076-sum-of-digits-of-string-after-convert
2163-kth-distinct-string-in-an-array
2470-removing-stars-from-a-string
2494-sum-of-prefix-scores-of-strings
2727-number-of-senior-citizens
2755-extra-characters-in-a-string
3235-minimum-cost-to-convert-string-i
3276-minimum-number-of-pushes-to-type-word-ii
3329-find-the-length-of-the-longest-common-prefix

Graph

0133-clone-graph
0207-course-schedule
0210-course-schedule-ii
0399-evaluate-division
0984-most-stones-removed-with-same-row-or-column
1325-path-with-maximum-probability
2171-second-minimum-time-to-reach-destination
2803-modify-graph-edge-weights
3235-minimum-cost-to-convert-string-i

Shortest Path

0399-evaluate-division
1325-path-with-maximum-probability
2171-second-minimum-time-to-reach-destination
2803-modify-graph-edge-weights
3235-minimum-cost-to-convert-string-i

Stack

0020-valid-parentheses
0071-simplify-path
0084-largest-rectangle-in-histogram
0094-binary-tree-inorder-traversal
0114-flatten-binary-tree-to-linked-list
0145-binary-tree-postorder-traversal
0150-evaluate-reverse-polish-notation
0155-min-stack
0173-binary-search-tree-iterator
0224-basic-calculator
0394-decode-string
0735-asteroid-collision
0776-n-ary-tree-postorder-traversal
1497-design-a-stack-with-increment-operation
1756-minimum-deletions-to-make-string-balanced
2470-removing-stars-from-a-string

Linked List

0019-remove-nth-node-from-end-of-list
0061-rotate-list
0082-remove-duplicates-from-sorted-list-ii
0086-partition-list
0092-reverse-linked-list-ii
0114-flatten-binary-tree-to-linked-list
0117-populating-next-right-pointers-in-each-node-ii
0138-copy-list-with-random-pointer
0146-lru-cache
0148-sort-list
0160-intersection-of-two-linked-lists
0206-reverse-linked-list
0328-odd-even-linked-list
0432-all-oone-data-structure
0725-split-linked-list-in-parts
0859-design-circular-deque
1484-linked-list-in-binary-tree
2411-spiral-matrix-iv
2903-insert-greatest-common-divisors-in-linked-list
3501-delete-nodes-from-linked-list-present-in-array

Two Pointers

0005-longest-palindromic-substring
0011-container-with-most-water
0019-remove-nth-node-from-end-of-list
0061-rotate-list
0080-remove-duplicates-from-sorted-array-ii
0082-remove-duplicates-from-sorted-list-ii
0086-partition-list
0088-merge-sorted-array
0148-sort-list
0151-reverse-words-in-a-string
0160-intersection-of-two-linked-lists
0189-rotate-array
0283-move-zeroes
0567-permutation-in-string
0719-find-k-th-smallest-pair-distance
1615-range-sum-of-sorted-subarray-sums
1798-max-number-of-k-sum-pairs
1923-sentence-similarity-iii
2581-divide-players-into-teams-of-equal-skill

Sorting

0056-merge-intervals
0088-merge-sorted-array
0148-sort-list
0169-majority-element
0179-largest-number
0452-minimum-number-of-arrows-to-burst-balloons
0502-ipo
0539-minimum-time-difference
0719-find-k-th-smallest-pair-distance
1256-rank-transform-of-an-array
1556-make-two-arrays-equal-by-reversing-subarrays
1615-range-sum-of-sorted-subarray-sums
1798-max-number-of-k-sum-pairs
2581-divide-players-into-teams-of-equal-skill
3276-minimum-number-of-pushes-to-type-word-ii

Hash Table

0003-longest-substring-without-repeating-characters
0012-integer-to-roman
0030-substring-with-concatenation-of-all-words
0036-valid-sudoku
0073-set-matrix-zeroes
0076-minimum-window-substring
0105-construct-binary-tree-from-preorder-and-inorder-traversal
0106-construct-binary-tree-from-inorder-and-postorder-traversal
0127-word-ladder
0133-clone-graph
0138-copy-list-with-random-pointer
0139-word-break
0146-lru-cache
0149-max-points-on-a-line
0160-intersection-of-two-linked-lists
0169-majority-element
0264-ugly-number-ii
0380-insert-delete-getrandom-o1
0432-all-oone-data-structure
0433-minimum-genetic-mutation
0567-permutation-in-string
0870-magic-squares-in-grid
0906-walking-robot-simulation
0920-uncommon-words-from-two-sentences
0984-most-stones-removed-with-same-row-or-column
0999-regions-cut-by-slashes
1256-rank-transform-of-an-array
1473-find-the-longest-substring-containing-vowels-in-even-counts
1556-make-two-arrays-equal-by-reversing-subarrays
1620-check-if-array-pairs-are-divisible-by-k
1694-make-sum-divisible-by-p
1786-count-the-number-of-consistent-strings
1798-max-number-of-k-sum-pairs
2163-kth-distinct-string-in-an-array
2581-divide-players-into-teams-of-equal-skill
2755-extra-characters-in-a-string
3276-minimum-number-of-pushes-to-type-word-ii
3329-find-the-length-of-the-longest-common-prefix
3501-delete-nodes-from-linked-list-present-in-array

Counting

0169-majority-element
0920-uncommon-words-from-two-sentences
1620-check-if-array-pairs-are-divisible-by-k
1786-count-the-number-of-consistent-strings
2163-kth-distinct-string-in-an-array
2494-sum-of-prefix-scores-of-strings
3276-minimum-number-of-pushes-to-type-word-ii

Breadth-First Search

0101-symmetric-tree
0102-binary-tree-level-order-traversal
0104-maximum-depth-of-binary-tree
0117-populating-next-right-pointers-in-each-node-ii
0127-word-ladder
0130-surrounded-regions
0133-clone-graph
0199-binary-tree-right-side-view
0200-number-of-islands
0207-course-schedule
0210-course-schedule-ii
0279-perfect-squares
0399-evaluate-division
0433-minimum-genetic-mutation
0945-snakes-and-ladders
0999-regions-cut-by-slashes
1484-linked-list-in-binary-tree
1691-minimum-number-of-days-to-disconnect-island
2035-count-sub-islands
2171-second-minimum-time-to-reach-destination

Design

0146-lru-cache
0155-min-stack
0173-binary-search-tree-iterator
0380-insert-delete-getrandom-o1
0432-all-oone-data-structure
0729-my-calendar-i
0731-my-calendar-ii
0789-kth-largest-element-in-a-stream
0859-design-circular-deque
1497-design-a-stack-with-increment-operation

Dynamic Programming

0005-longest-palindromic-substring
0022-generate-parentheses
0045-jump-game-ii
0055-jump-game
0072-edit-distance
0097-interleaving-string
0118-pascals-triangle
0122-best-time-to-buy-and-sell-stock-ii
0139-word-break
0152-maximum-product-subarray
0198-house-robber
0221-maximal-square
0241-different-ways-to-add-parentheses
0264-ugly-number-ii
0279-perfect-squares
0650-2-keys-keyboard
0664-strange-printer
0954-maximum-sum-circular-subarray
1196-filling-bookcase-shelves
1240-stone-game-ii
1511-count-number-of-teams
1756-minimum-deletions-to-make-string-balanced
2067-maximum-number-of-points-with-cost
2755-extra-characters-in-a-string

Binary Indexed Tree

1511-count-number-of-teams

Binary Search

0004-median-of-two-sorted-arrays
0033-search-in-rotated-sorted-array
0034-find-first-and-last-position-of-element-in-sorted-array
0035-search-insert-position
0074-search-a-2d-matrix
0153-find-minimum-in-rotated-sorted-array
0162-find-peak-element
0209-minimum-size-subarray-sum
0222-count-complete-tree-nodes
0719-find-k-th-smallest-pair-distance
0729-my-calendar-i
0731-my-calendar-ii
1615-range-sum-of-sorted-subarray-sums
2006-find-the-student-that-will-replace-the-chalk

Tree

0094-binary-tree-inorder-traversal
0098-validate-binary-search-tree
0101-symmetric-tree
0102-binary-tree-level-order-traversal
0104-maximum-depth-of-binary-tree
0105-construct-binary-tree-from-preorder-and-inorder-traversal
0106-construct-binary-tree-from-inorder-and-postorder-traversal
0108-convert-sorted-array-to-binary-search-tree
0114-flatten-binary-tree-to-linked-list
0117-populating-next-right-pointers-in-each-node-ii
0129-sum-root-to-leaf-numbers
0145-binary-tree-postorder-traversal
0173-binary-search-tree-iterator
0199-binary-tree-right-side-view
0222-count-complete-tree-nodes
0230-kth-smallest-element-in-a-bst
0236-lowest-common-ancestor-of-a-binary-tree
0437-path-sum-iii
0543-diameter-of-binary-tree
0772-construct-quad-tree
0776-n-ary-tree-postorder-traversal
0789-kth-largest-element-in-a-stream
0904-leaf-similar-trees
1484-linked-list-in-binary-tree

Binary Tree

0094-binary-tree-inorder-traversal
0098-validate-binary-search-tree
0101-symmetric-tree
0102-binary-tree-level-order-traversal
0104-maximum-depth-of-binary-tree
0105-construct-binary-tree-from-preorder-and-inorder-traversal
0106-construct-binary-tree-from-inorder-and-postorder-traversal
0108-convert-sorted-array-to-binary-search-tree
0114-flatten-binary-tree-to-linked-list
0117-populating-next-right-pointers-in-each-node-ii
0129-sum-root-to-leaf-numbers
0145-binary-tree-postorder-traversal
0173-binary-search-tree-iterator
0199-binary-tree-right-side-view
0222-count-complete-tree-nodes
0230-kth-smallest-element-in-a-bst
0236-lowest-common-ancestor-of-a-binary-tree
0437-path-sum-iii
0543-diameter-of-binary-tree
0789-kth-largest-element-in-a-stream
0904-leaf-similar-trees
1484-linked-list-in-binary-tree

Math

0012-integer-to-roman
0048-rotate-image
0050-powx-n
0149-max-points-on-a-line
0150-evaluate-reverse-polish-notation
0189-rotate-array
0224-basic-calculator
0241-different-ways-to-add-parentheses
0264-ugly-number-ii
0273-integer-to-english-words
0279-perfect-squares
0380-insert-delete-getrandom-o1
0539-minimum-time-difference
0564-find-the-closest-palindrome
0592-fraction-addition-and-subtraction
0650-2-keys-keyboard
0870-magic-squares-in-grid
1240-stone-game-ii
2155-find-missing-observations
2903-insert-greatest-common-divisors-in-linked-list

Recursion

0050-powx-n
0206-reverse-linked-list
0224-basic-calculator
0241-different-ways-to-add-parentheses
0273-integer-to-english-words
0394-decode-string

Depth-First Search

0094-binary-tree-inorder-traversal
0098-validate-binary-search-tree
0101-symmetric-tree
0104-maximum-depth-of-binary-tree
0114-flatten-binary-tree-to-linked-list
0117-populating-next-right-pointers-in-each-node-ii
0129-sum-root-to-leaf-numbers
0130-surrounded-regions
0133-clone-graph
0145-binary-tree-postorder-traversal
0199-binary-tree-right-side-view
0200-number-of-islands
0207-course-schedule
0210-course-schedule-ii
0230-kth-smallest-element-in-a-bst
0236-lowest-common-ancestor-of-a-binary-tree
0399-evaluate-division
0437-path-sum-iii
0543-diameter-of-binary-tree
0776-n-ary-tree-postorder-traversal
0904-leaf-similar-trees
0984-most-stones-removed-with-same-row-or-column
0999-regions-cut-by-slashes
1484-linked-list-in-binary-tree
1691-minimum-number-of-days-to-disconnect-island
2035-count-sub-islands

Topological Sort

0207-course-schedule
0210-course-schedule-ii

Union Find

0130-surrounded-regions
0200-number-of-islands
0399-evaluate-division
0984-most-stones-removed-with-same-row-or-column
0999-regions-cut-by-slashes
2035-count-sub-islands

Matrix

0036-valid-sudoku
0048-rotate-image
0054-spiral-matrix
0073-set-matrix-zeroes
0074-search-a-2d-matrix
0079-word-search
0130-surrounded-regions
0200-number-of-islands
0212-word-search-ii
0221-maximal-square
0289-game-of-life
0772-construct-quad-tree
0870-magic-squares-in-grid
0921-spiral-matrix-iii
0945-snakes-and-ladders
0999-regions-cut-by-slashes
1691-minimum-number-of-days-to-disconnect-island
2035-count-sub-islands
2132-convert-1d-array-into-2d-array
2411-spiral-matrix-iv

Greedy

0011-container-with-most-water
0045-jump-game-ii
0055-jump-game
0122-best-time-to-buy-and-sell-stock-ii
0134-gas-station
0179-largest-number
0452-minimum-number-of-arrows-to-burst-balloons
0502-ipo
0624-maximum-distance-in-arrays
0890-lemonade-change
3276-minimum-number-of-pushes-to-type-word-ii

Sliding Window

0003-longest-substring-without-repeating-characters
0030-substring-with-concatenation-of-all-words
0076-minimum-window-substring
0209-minimum-size-subarray-sum
0567-permutation-in-string
2255-minimum-swaps-to-group-all-1s-together-ii

Simulation

0054-spiral-matrix
0068-text-justification
0289-game-of-life
0592-fraction-addition-and-subtraction
0735-asteroid-collision
0906-walking-robot-simulation
0921-spiral-matrix-iii
2006-find-the-student-that-will-replace-the-chalk
2076-sum-of-digits-of-string-after-convert
2132-convert-1d-array-into-2d-array
2155-find-missing-observations
2411-spiral-matrix-iv
2470-removing-stars-from-a-string

Binary Search Tree

0098-validate-binary-search-tree
0108-convert-sorted-array-to-binary-search-tree
0173-binary-search-tree-iterator
0230-kth-smallest-element-in-a-bst
0789-kth-largest-element-in-a-stream

Randomized

0380-insert-delete-getrandom-o1

Prefix Sum

0209-minimum-size-subarray-sum
0238-product-of-array-except-self
0731-my-calendar-ii
1240-stone-game-ii
1435-xor-queries-of-a-subarray
1473-find-the-longest-substring-containing-vowels-in-even-counts
1694-make-sum-divisible-by-p
1833-find-the-highest-altitude
2006-find-the-student-that-will-replace-the-chalk

Doubly-Linked List

0146-lru-cache
0432-all-oone-data-structure

Strongly Connected Component

1691-minimum-number-of-days-to-disconnect-island

Heap (Priority Queue)

0264-ugly-number-ii
0373-find-k-pairs-with-smallest-sums
0502-ipo
0789-kth-largest-element-in-a-stream
1325-path-with-maximum-probability
2803-modify-graph-edge-weights

Data Stream

0789-kth-largest-element-in-a-stream

Iterator

0173-binary-search-tree-iterator

Backtracking

0022-generate-parentheses
0040-combination-sum-ii
0046-permutations
0079-word-search
0212-word-search-ii

Merge Sort

0148-sort-list

Queue

0859-design-circular-deque
0954-maximum-sum-circular-subarray

Monotonic Queue

0954-maximum-sum-circular-subarray

Trie

0139-word-break
0212-word-search-ii
0440-k-th-smallest-in-lexicographical-order
2494-sum-of-prefix-scores-of-strings
2755-extra-characters-in-a-string
3329-find-the-length-of-the-longest-common-prefix

Memoization

0139-word-break
0241-different-ways-to-add-parentheses

Geometry

0149-max-points-on-a-line

Monotonic Stack

0084-largest-rectangle-in-histogram

Game Theory

1240-stone-game-ii

Number Theory

2903-insert-greatest-common-divisors-in-linked-list

Brainteaser

2503-longest-subarray-with-maximum-bitwise-and

Rolling Hash

0214-shortest-palindrome

String Matching

0214-shortest-palindrome

Hash Function

0214-shortest-palindrome

Segment Tree

0729-my-calendar-i
0731-my-calendar-ii

Ordered Set

0729-my-calendar-i
0731-my-calendar-ii